1. Field of the Invention
The invention relates to a chip on lead package and a method for making the same, particularly to a flip chip on leadframe package and the method of making the same.
2. Description of the Related Art
FIGS. 1 to 6 show a conventional method for making a flip chip on leadframe package. Firstly, referring to FIG. 1, a leadframe 10 having a plurality of inner leads 11 is provided. Each inner lead 11 has a first surface 111 and a second surface 112. Referring to FIG. 2, a chip 12 having an active surface 121 is provided. A plurality of bumps 13 are formed on the active surface 121 of the chip 12, wherein each bump 13 has substantially the same volume and height. Referring to FIG. 3, the top of the bumps 13 are dipped in a flux 14 so that the flux 14 attaches to the bumps 13. Referring to FIG. 4, the bumps 13 contact the first surface 111 of the corresponding inner leads 11. Referring to FIG. 5, a reflow step proceeds so that the bumps 13 are melted and connected to the first surface 111 of the inner leads 11. Finally, referring to FIG. 6, a molding material 15 is used to encapsulate the first surface 111 of the inner leads 11, the chip 12, and the bumps 13 to form a flip chip on leadframe package 1.
The conventional method has the following shortcomings. In FIG. 5, the bumps 13 are melted so that the bumps 13 cannot support the chip 12 when reflowing. Therefore, the gap between the active surface 121 of the chip 12 and the first surface 111 of the inner leads 11 cannot be controlled with assurance, so that the chip 12 collapses easily to cause damage to the bumps 13, and the flip chip bonding is not good.
Consequently, there is an existing need for providing a flip chip on leadframe package and a method for making the same to solve the above-mentioned problems.